After threatening to back out of the 2015 nuclear deal “within hours” if faced with new American sanctions, Iranian President Hassan Rouhani added that if Tehran restarted its nuclear program, it would be “far more advanced” than it was before nuclear negotiations began in 2013.

The New York Timesasserted[1] on Tuesday that with a more advanced nuclear program, Iran “could start enriching uranium up to the level of 20 percent, a step toward building a nuclear weapon.”

But was Rouhani making a threat? Or did he accidentally admit that even now Iran is engaged in clandestine nuclear weapons research, in violation of the nuclear deal?

One of the weaknesses of the accord is that it doesn’t force Iran to reveal the full extent of its past nuclear research.

In December 2015, a month and a half before Implementation Day, the International Atomic Energy Agency (IAEA) released a report[2] that found that Iran had engaged in nuclear weapons research until at least 2009. The IAEA, which is the nuclear watchdog of the United Nations and is in charge of monitoring Iran’s compliance with the nuclear deal, couldn’t say for certain whether Iran had stopped seeking nuclear weapons because Iran withheld information.

In June 2016, the Obama administration acknowledged[3] that traces of enriched uranium found at the Parchin military installation were likely the result of Iran’s nuclear weapons research.

In addition to the unresolved questions raised by the final IAEA report on Iran’s past nuclear work, a former Obama administration official told[4]The New York Times in 2013 that “there has never been a time in the past 15 years or so when Iran didn’t have a hidden facility in construction.”

There also is a historical reason to suspect that Iran is cheating on the nuclear deal. That is because when it reached an agreement with the United Kingdom, France and Germany in 2004, Iran cheated on its commitments too.

In November 2004, Iran and the three European nations, known collectively as the EU3, agreed that Iran would stop enriching uranium in order to avoid being referred to the UN Security Council for violating the Nuclear Non-Proliferation Treaty.

The foreign ministers of the three countries brokered a deal, announced with much fanfare in Tehran 13 months ago. In it, Iran agreed to suspend its production of enriched uranium, which can be used in nuclear energy or nuclear weapons programs, and to submit to more intrusive inspections of its nuclear facilities.

After Iran violated the agreement, officials from the three countries acknowledged that the deal had been made too hastily and that the language of the final accord was too vague and open to misinterpretation.

However, within a year, Iran announced[6] its rejection of the Paris agreement, saying that the incentives offered by the Europeans for it not to pursue a military nuclear program were “not acceptable.” Two days later, on August 8, Iran restarted[7] its uranium enrichment program.

In response to Iran’s rejection of the deal, the Europeans said that they would refer Iran’s case to the Security Council. Beginning in July 2006, the Security Council would approve at least six resolutions (1696[8], 1737[9], 1747[10], 1803[11], 1835[12], and 1929[13]) sanctioning Iran for its illicit nuclear program as it repeatedly refused to halt enriching uranium. (The nuclear deal removed the nuclear-related sanctions and allowed Iran to maintain its enrichment program.)

If Iran was concerned about the consequences of defying the Europeans, their lead nuclear negotiator for the Paris agreement didn’t show it.

Hassan Rouhani, now president of Iran, told a closed meeting of clerics in March 2006 that the negotiations allowed Iran to advance their nuclear program.

“From the outset, the Americans kept telling the Europeans, ‘The Iranians are lying and deceiving you and they have not told you everything.’ The Europeans used to respond, ‘We trust them’,” The Telegraphreported[14].

“When we were negotiating with the Europeans in Teheran we were still installing some of the equipment at the Isfahan site. There was plenty of work to be done to complete the site and finish the work there. In reality, by creating a tame situation, we could finish Isfahan,” Rouhani added.

“The dilemma was if we offered a complete picture, the picture itself could lead us to the UN Security Council,” he said, speaking of the predicament Iran was facing in September 2003, when the IAEA demanded a full accounting of its nuclear activities. “And not providing a complete picture would also be a violation of the resolution and we could have been referred to the Security Council for not implementing the resolution.”

Rouhani made similar boasts in 2013 when he was running for his first term as president. During a televised debate, when the moderator accused Rouhani of suspending Iran’s nuclear program for negotiations, the candidate pushed back:

Quite the contrary, Rouhani countered, detailing the completion of various phases of work at Isfahan under his watch in 2004 and 2005. He went on to state proudly that the Iranian heavy water reactor at Arak was also developed under his watch, in 2004.

“Do you know when we developed yellowcake? Winter 2004,” Rouhani went on. “Do you know when the number of centrifuges reached 3,000? Winter 2004.”

Incredulous at the notion that Iran had bowed to international pressure and halted nuclear activities in that period, Rouhani asked the interviewer, “We halted the nuclear program? We were the ones to complete it! We completed the technology.”

Not once—but twice—did Iran’s one-time nuclear negotiator admit that the Islamic Republic engaged in negotiations with the West to deceive the world and allow it to advance its illicit nuclear research.

Now he’s president.

What are the chances that the negotiations from 2013 to 2015 were also a distraction, “creating a tame situation” in Rouhani’s words, giving Iran the money it needed to advance its nuclear research and develop nuclear weapons?